Marking systems that transport paper or other media are well known in the art. These marking systems include electrostatic marking system, non-electrostatic marking systems, printers or any other marking system where paper or other flexible media or receiving sheets are transported internally to an output device, such as a finisher and compiler. Many systems are used for transporting, collecting, or gathering printed sheets so that they may be formed into books, pamphlets, forms, sales literature, instruction books and manuals and the like. For simplicity and clarity the present invention will be described in relation to an electrostatic marking system; however, the present system may be used in any paper handling system or structure.
The finisher and compiler are generally located at a site in these marking systems after the receiving sheets (paper) have been marked. A finisher is generally defined as an output device that has various post printer functions or options such as hole punching, corner stapling, edge stapling, sheet and set stacking, letter or tri-folding, Z-folding, Bi-folding, signature booklet making, set binding [including thermal, tape and perfect binding], trimming, post process sheet insertion, saddle stitching and others.
The compiler often employs a compiling wall or tray where frictional drive elements hereinafter elastomer paddle wheels or “paddle wheels” (PW) are used to drive media sheets (paper) against the compiling wall for registration of the staple or bind edge of a set. These sheets in today's high speed printers and multi-functional machines may be fed to a compiling wall or other post processing means by high speed multi-feeders.
The compiling capacity, bind edge sheet registration and post printing steps can be compromised by these high speed multi-feeds system where an unintended extra sheet destroys the integrity of a collated set or sequence of post processing functions. These functions, as above noted, include finishing stations, envelope stuffers and similar processing where inconsistent feeding systems destroy the integrity and unreliability of a set of media fed thereto. Some current multi-detectors have had limited success because they work with paper stiffness properties and media varies from job to job. Other multi-feed systems work with ultrasonic sensors and are relatively expensive. A feed system that is less expensive, simple and less dependent on media type would be a huge step forward. Even ordinary offices are stepping up their efforts at in-house production of conference paper, simple booklets, manuals and other materials by establishing service departments for intensively processing prints in large quantities. Such customers require post-processing functions, such as high-speed/high-precision punching, stapling and paper folding work with simultaneous print output and realization of high-speed/high-quality print output with a high degree of reliability of the feeders.